Note: Descriptions are shown in the official language in which they were submitted.
w
CA 02392934 2002-07-10
- 1
CONCRETE STONE TEXTURING MACHINE,
METHOD AND PRODUCT
TECHNICAL FIELD
tooo~l The present invention relates to a concrete stone
facing machine, its method of operation and the resulting
concrete stone block having an irregular rough surface which
is chipped to resemble a real stone face.
BACKGROUND ART
foooal There has been a need for several decades to
develop a machine capable of facing stones by chipping the
stone to form a rough surface resembling a real stone. For
example, in U.S. Patent 2,867,204, issued on January 6,
1959, there is proposed a machine which is provided with two
opposed chisels vuhich are disposed against opposed surfaces
of a stone adjacent a face to be roughened. These chisels
are impacted by hammers whereby to simulate a conventional
method that a mason uses to chip a stone. U.S. Patent
2,912,969, also issued in 1959, describes a stone dressing
and planing machine which utilizes a pair of opposed
vertically movable, horizontal blades and a pair of vertical
blades operated by rams. These pair of blades are actuated
in unison, one after the other whereby to square face stone
blocks or rubble stones which are used for erecting
buildings. This machine is not for chipping a stone to form
an irregular rough surface to resemble a real stone face.
Iooo31 More recently, with the advent of paving stones
formed from concrete molds, a need has developed to roughen
these prefabricated stones to resemble a real stone which
has rounded and fragmented edges and surfaces. This is
usually done by tumbling the stones in large cylindrical
tumblers whereby the stone impacts abrading elements
provided on an inner surface of the cylindrical containers
as well as impacting one another. This has been a costly
and hazardous operation as a percentage of the tumble stones
CA 02392934 2002-07-10
will fragment and then have to be discarded. They are also
labour intensive, result in injuries and the operation is
very physical requiring shift work of short duration.
However, this roughened or abraded process is only
superficial on the surfaces and edges of the black and do
not deeply penetrate the surfaces. Real stone faces have a
deeper and irregular texture which these machines and
process cannot achieve.
DISCLOSURE OF INVENTION
Iooo4~ It is a feature of the present invention to
provide a concrete stone facing machine which substantially
overcomes the disadvantages of the prior art and meets the
needs for production of concrete stones having a projecting"
irregular front rough surface to resemble a real stone face.
tooosl According to a further object of the present
invention there is provided a method of forming a projecting
irregular rough surface in a face of a concrete stone having
opposed flat faces whereby the front face is textured to
resemble a real irregular stone face.
tooosl According to a still further feature of the
present invention, there is provided a pitching blade
assembly for use in a concrete stone facing machine whereby
to pitch a concrete stone about its periphery to form an
irregular rough projecting front face.
tooo~l According to a still further feature of the
present invention there is provided a concrete stone having
opposed flat walls surrounding a projecting irregular rough
front face resembling a real stone face.
toooal According to the above features, from a broad
aspect, there is provided a concrete stone facing machine
comprising means to convey a stone having opposed flat
surfaces to a pitching station where a predetermined one of
said surfaces of said stone is to be pitched to form a deep
irregular rough surface to resemble a real stone face . At
least one pair of opposed pitching blade assemblies are
CA 02392934 2002-07-10
- 3 -
aligned in a common plane on a respective side of said
pitching station. Means is provided to displace each of the
pitching blade assemblies towards and away from one another
a predetermined distance. Each pitching blade assembly has
a plurality of pitching blades secured in side-by-side
aligned relationship. Each pitching blade assembly has a
forward projecting cutting edge and a securing body portion.
A first group of the pitching blades has their cutting edges
aligned with a first straight cutting axis which is offset
from the cutting edges of a second group of pitching blades
and aligned along a second straight cutting axis. The
cutting axes are parallel to one another.
tooosl The present invention also provides a method of
forming a deep irregular rough surface in a face of a
concrete stone having flat faces whereby said face is
textured to resemble a real irregular chipped stone face.
The method comprises the steps of: i) Conveying a concrete
stone in a predetermined oriented position to a loading
station adjacent a pitching station. ii) Arresting said
stone at a predetermined position at said loading station in
alignment with said pitching station. iii) Providing at
said pitching station two pairs of opposed blade assemblies,
one pair being horizontal pitching blade assemblies and
another pair being vertical pitching blade assemblies. Each
of the pitching blade assemblies have a plurality of
pitching blades secured in side-by-side relationship. Each
pitching blade has a forward projecting cutting edge and a
securing body portion. A first group of the pitching blades
has their cutting edges aligned with a first straight
cutting axis which is offset from the cutting edges of a
second group of pitching blades aligned along a second
straight cutting axis. The cutting axes are parallel to one
another. The pitching blade assemblies lie in a common
vertical plane. iv) Positioning the stone by pusher means
to the pitching station with the face to be textured
projecting a predetermined distance within the common plane.
r
CA 02392934 2002-07-10
- 4 -
v) Displacing the pitching blade assemblies simultaneously
to cause the pitching blades to move into surrounding,
substantially transverse, surfaces of the face a
predetermined distance to chip the face to form an irregular
rough surface. vi) Discharging the concrete block with the
chipped irregular rough surface.
Ioooiol The present invention also provides a pitching
blade assembly for use in a concrete stone facing machine to
pitch a concrete stone to form a deep irregular rough
surface in a face of the stone surrounded by opposed flat
surfaces. The pitching blade assembly comprises a blade
holder and a plurality of pitching blades secured in side-
by-side aligned relationship to he blade holder. Each said
pitching blade has a forward projecting cutting edge and a
securing body portion. A first group of the pitching blades
has a forward projecting cutting edge and a securing body
portion. A first group of the pitching blades has their
cutting edges aligned with a first straight cutting axis
which is offset from the cutting edges of a second group of
pitching blades aligned along a second straight cutting
axis. The cutting axes are parallel to one another.
Loo~oml The present invention still further provides a
concrete stone having opposed flat walls surrounding a deep
irregular rough surface resembling a real stone face. The
opposed flat walls have, immediately adjacent the deep rough
surface, two groups of spaced apart blade indentations
aligned along respective straight parallel axes with at
least some of the blade indentations being fragmented or
partially fragmented.
BRIEF DESCRIPTION OF THE DRAWLNGS
Iooola~ A preferred embodiment of the present invention is
now described with reference to the following drawings in
which:
a
CA 02392934 2002-07-10
- 5 -
tooo~3l FIG. 1 is a front perspective view of the concrete
stone facing machine with the frame of the machine
illustrated phantom lines;
in
1000141 FIG. 2 is a perspective view similar to Figure
1,
but viewed
from the
rear of the
machine;
tooo~5) FIG. 3 is a tap view of the concrete stone facing
machine of present invention;
the
100016) FIG. 4 is a front view thereof , illustrating
the
pitching station
and the pitching
blade assemblies;
tooo~~J FIG. 5 is a plan view of a pitching blade
assembly;
Iooola) FIG. 6 is an end view of Figure 5;
tooolsl FIG. 7 is an enlarged view illustrating the
construction of the pitching blades and their offset
alignment;
toooaol FIG. 8A is a side view of a stop bar assembly;
fooo211 FIG. 8B is a top view of Figure 8A;
1000221 FIG. 9A is a side view of the pusher bar assembly;
tooo23) FIG. 9B is a top view of the pusher bar assembly
of Figure
9A;
fooo24) FIG. 10A is a side view of the stone discharge
lift-off assembly;
IoooaS) FIG. lOB is a right end view of Figure 10A;
Ioooz6J FIG. lOC is a top view of Figure 10A;
toooa~l FIG. 11 is a perspective view of a concrete stone
having a deep
irregular
rough surface
formed with
the
machine and thod of the present invention;
me
toooael FIG. 12 is an enlarged view of a fragmented
portion of stone of Figure 11;
the
1000291 FIG. 13 is a transverse cross-sectional view
illustrating
the deep
irregular
rough surface
formed in
a
face of the
concrete
stone;
1000301 FIG. 14 is a perspective view illustrating a stone
inverting
cradle disposed
along the
conveyor
line whereby
to
invert stones;
CA 02392934 2002-07-10
6
tooo3i~ FIG. 15A is a simplified schematic view of a stone
surfacing assembly; and
(00032 FIG. 15B is a side view of a stone to be treated
by the surfacing assembly of Figure 15A.
MODES FOR CARRYING OUT THE INVENTION
tooo3sl Referring now to the drawings, and more
particularly to Figures 1 to 4, there is illustrated a
concrete stone facing machine 1 constructed in accordance
with the present invention whereby to fabricate the concrete
stone 2, as illustrated in Figure 11, which is formed with
opposed surrounding flat walls 3 and 3' and having a
projecting irregular rough front surface 4 which resembles a
real atone face. As shown in Figure 11, the stones produced
by the machine 1 of the present invention have in their
opposed flat walls, and immediately adjacent the deep rough
contour of its front surface 4, two groups of spaced apart
blade indentations, namely, group 5 and group 6 of blade
indentations and which are aligned along respective
straight, parallel axes 5' and 6'. These are also present
on the side faces 3'. These blade indentations and their
offset are herein shown exaggerated to illustrate that there
is a small spacing between them to achieve the texturing of
the front face 4 of the concrete stone. The concrete stone
produced also has some of its blade indentations 5 and 6
which are fragmented or partly fragmented, as illustrated by
reference numerals 7 and this is due to the aggregate in the
stone and the configuration of the pitching blades as will
be described later on. As also shown in Figure 11, these
blade indentations are substantially of equal lengths but
this is not essential. It is further pointed out that one
of the groups, group 6, of blade indentations are deeper
than the indentations of the other group and this results in
achieving a deep irregular rough surface configuration,
particularly in the outer peripheral regions 4' of the front
surface 4. The two groups of indentations are also formed
CA 02392934 2002-07-10
in alternate sequence along the respective straight parallel
axes, but this alternate sequence is also not essential and
it is conceivable that this sequence could be irregular.
tooo341 The reference to "pitching" as used herein means
that a face of a concrete block' is given a deep irregular
rough surface by chipping said surface by the use of blades
penetrating surrounding substantially transverse surfaces of
the face of the block to be pitched such that irregular size
stone chips are broken off the surface being chipped.
Before the concrete stone 2 is pitched, a large square stone
usually twice the size of the stone 2 is split in halt to
produce a rough aggregate surface 4. The blades then pitch
the stone about a contour edge portion to chip the stone to
form deep indentations so that the face 4 projects forwardly
and is rough like a real stone.
tooo351 As shown in Figures 12 and 13, the indentations
formed by the pitching blade illustrated by arrow 8 produces
a much deeper cut into the stone face 3 which results in a
large deeper chip being broken off the stone face 4 as
illustrated by the fragmented surface 8'. The alternate
pitching blade indentation formed by the pitching blade
illustrated by arrow 9, produces a smaller irregular chip
illustrated by the fragmented surface 9' and the chip 9".
Because these blades are alternate or are disposed in a
predetermined sequence, they produce alternate rough cuts
which are deep and shallow and the fragmentation also
depends on the aggregate composition of the concrete stone
which is not predictable. Accordingly, all of the pitched
stone faces produced by the concrete stone facing machine 1
of the present invention are different from one another.
Iooossl Reverting now to Figures 1 to 4, there will be
described the construction and operation of the concrete
stone facing machine 1 of the present invention. The
machine 1 has a frame l' to which is mounted an infeed
conveyor l0 which feeds concrete stones 11 having a rough
front face 11', caused by a larger stone having been split.
CA 02392934 2002-07-10
-a-
The front face 11' is surrounded by opposed flat parallel
surfaces adjacent thereto. The infeed conveyor l0 is formed
by a plurality of feed rolls 12 which are driven by an
endless chain drive, not shown but concealed in a chain
housing 13 whereby to rotate the feed rollers 12 and feed
stones 11 to the machine, in a controlled manner. The
spacing between the stones 11 is synchronized with the
machine operation.
(00031 As the stones 11 are fed to the machine in the
direction of arrow 14, they will be stopped at a
predetermined position as dictated by a stop bar 15. The
stop bar 15 is adjustably positioned by a motor driven
assembly 16 as will be described later. The positioning of
the atop bar is to precisely align the stones 11 conveyed
thereto in relation to a pitching station 17, as better
illustrated in Figure 4, and the size of the stone. The
control unit 100 is inputted information signal concerning
the stone sizes and quantities and controls the operation of
the stop bar motor drive assembly 16.
Iooo3s) At the pitching station 17, there is provided at
least one pair of opposed pitching blade assemblies 18 and
18' and as hereinshown there axe two pairs of pitching blade
assemblies, namely a horizontal pair 18 and 18' and a
vertical pair of pitching blade assemblies 19 and 19'. As
shown in Figure 5, wherein there is illustrated the vertical
pitching blade assembly 19, each blade assembly comprises a
plurality of pitching blades 20 secured in side-by-side
aligned relationship and are secured to a blade holder 21
provided with holes 22 whereby to secure same to a piston
connecting frame 23 which is displaced by a hydraulic
cylinder 24. The blade holder is maintained in a perfectly
vertical plane by guide rods 25 secured in a guide frame 26.
This type of arrangement is also provided for each of the
opposed pitching blade assemblies which are each provided
with their own hydraulic cylinders 24. With additional
reference to Figure 7, it can be seen that there are two
c
~ CA 02392934 2002-07-10
- 9 -
groups of pitching blades and they are hereinshown as
secured to the pitching blade holder 22 in alternating side-
by-side relationship. 'Thus, there is a first group 20 of
blades and a second group 20'.
tooo391 As better illustrated in Figure 7, each of the
pitching blades 20 and 21 have a forward projecting cutting
edge 26 for blade 20 and 26' for blade 20' and securing body
portions 27 and 27'. These body portions 27 and 27' are
secured in a channel 28 formed in a front face 29 of the
holder 21 and secured therein by a two-component glue
material, well known in the art, or other means.
tooo~ol A first group, namely pitching blades 20, have
their straight cutting edges 26 aligned along a first
straight cutting axis 5' which corresponds to the axis as
previously described with reference to Figure 1l and the
second group of pitching blades 20' have their straight
cutting edge 26' aligned along a second straight cutting
axis 6'. As also shown in Figure 7, the second group of
pitching blades 20' have their straight cutting edge
recessed below the projecting cutting edge 26 of the first
group. They are also recessed rearwardly thereof a distance
as illustrated by the offset of the axes 5' and 6' . Also,
the cutting heads of these two groups of pitching blades are
differently configured from one another whereby to obtain
the deep irregular rough surface 4 in the chip stone face.
tooo4~) Again referring to Figure 7, it can also be seen
that the cutting heads have a transverse pyramidal shape
which defines a forward rearwardly inclined front bevel face
30 for pitching blade 20 and 30' for pitching blade 20'
leading to their respective elongated straight cutting edges
26 and 26', and a rearwardly inclined rear bevel face 31 and
31' respectively, depending from their respective cutting
edges 26 and 26'. The front bevel faces 30 and 30' and the
rear bevel faces 31 and 31' from both groups of pitching
blades, extend at different angles. As hereinshown the
front bevel faces of the cutting blades of the first group
v
CA 02392934 2002-07-10
1~
20 extend at a common angle which is different than their
rear face 31. These angles are also different than the
cutting blades of the second group, as above mentioned. As
hereinshown, the front bevel face 30' of the second group of
pitching blades 20' are shallower (less steep) than their
rear bevel face 31' . Also, the front bevel faces 30 of the
cutting heads of the first group of pitching blades are much
steeper than their rear bevel face 31 whereby to chip
different size concrete chips from a stone face to form the
deep irregular rough surface when the pitching blades are
pitched to penetrate the flat surfaces adjacent the face to
be chipped. Also; the front bevel faces 30 of the first
group of pitching blades are much steeper than those of the
second group of pitching blades.
Iooo42~ As shown in Figure 6, the blade holder 21 is
secured to the frame 23 by suitable fasteners, not shown.
Also secured to the frame 23 is a stopper bar 23' which has
an abutment face 23" to abut a surrounding surface 3 or 3'
of a stone 2 to be pitched. The spacing between the leading
cutting edge 26 of the blade 20 and the abutment face 23"
defines the penetration of the blades within the stone being
pitched. This topper bar 23' can also be referred to as an
equalizing bar as it ensures that opposed surfaces of a
stone are penetrated an equal distance by opposed parallel
blade assemblies. That is to say, if one blade assembly
penetrates the block an instant before the other blade
assembly of a pair, it will provide a backing until the
other assembly fully penetrates by its piston stroke. Of
course, we are talking of a fraction of a second. The
distance of penetration "x", as shown in Figure 6, is
adjustable by changing the stopgex bar 23' and a preferred
distance of penetration for a 12 inch block is about 8 mm.
Iooo431 As shown in Figure 1, there are two pairs of
opposed pitching blade assemblies, namely the horizontal
pitching blade assemblies 18 and 18' and the vertical
pitching blade assemblies 19 and 19' and they are all
CA 02392934 2002-07-10
- 11 -
aligned in a common vertical plane at the pitching station
17. It is also pointed out that the piston connecting
frames 23 supporting each of the pitching blade assemblies
are each provided with a pressure sensor 32 to sense the
resistance, namely when the cutting edge 26 which is the
most projecting edge of the groups of pitching blades,
contacts their respective opposed flat side surfaces 3 and
3' of a stone 11 to be pitched. Their respective cylinders
24 advance the cutting edges to contact the stone faces and
then momentarily stop. As soon as all stone faces have been
contacted by each of the pitching blade assemblies or by a
pair of blade assemblies if a stone is pitched alternately
by the horizontal blades and then the vertical blades, the
cylinder will displace the cutting heads into the surfaces
at a higher pressure as controlled by the controller 100 and
the hydraulic circuit 101 and hydraulic valve 102. The
stroke or penetration is limited by the stopper bar 23'.
The penetration is usually set between 4 to 10 mm depending
on the size of the block. This will cause concrete stone
material to be pitched off the surface surrounding the
opposed flat side walls and give the fragmented stone face 4
a much deeper fragmented appearance.
tooo44~ It is pointed out that the machine also comprises
a pushing bar assembly 33 which pushes a stone 11, which is
arrested by the stop bar 15, to a precise position at the
pitching station 17 onto a pitching platform 34 with the
front face 4 of the stone 11 projecting beyond the plane
defined by the opposed cutting edges of the pitching blade
assemblies. This positioning of the stone is preprogrammed,
depending on the size and configuration of the stones 11
being pitched. Pitching bar assembly 33 will be described
later, but is controlled by a motor drive to slowly displace
the stone from the stop bar and move it to the pitching
station and slowly position it at the proper location. Once
the stone reaches its proper position, a top clamp bar 35
clamps the stone on the pitching platform 34 and the
CA 02392934 2002-07-10
a
- 12 -
pitching blade assemblies are displaced in pairs or all at
the same time to contact the stone and momentarily arrested
before their cylinders actuate their second stroke at higher
pressure to fragment the stone face. The clamp bar 35 is
supported on guide rods 37 secured between guide wheels 38
disposed between guide plates 39.
tooo4s) The hydraulic cylinders 24 of each group of
pitching blade assemblies, namely the horizontal and
vertical groups, are controlled by respective hydraulic
valves 102 whereby the pressure sensors 32 would provide
signals to the controller 100, which then operate the
hydraulic cylinder to effect their second stroke. It is
pointed out that the cylinders 24 are actuated in pairs or
simultaneously to effect the second stroke whereby the stone
face is fabricated in a single cycle or two cycles. Of
course, the vertical blade assemblies are shorter to move
between the horizontal assembly during the second stroke.
tooo4s) As shown in Figure 1, the pitching platform 24 is
a slotted platform provided with slots 40. The platform
also has a projecting edge 41 and is open thereunder. A pit
42 is provided under the pitching station 17 whereby chipped
concrete particles and dust particles would fall directly
into the pit 42 which is provided with a conveyor 42' to
convey debris away from the machine. The frames 23 secured
to the blade holders 21 are secured to an intermediate frame
43 by an articulated connection, not shown, to compensate
for irregularities in the flat surfaces of the stones which
are contacted by the blade. These irregularities are
usually very small irregularities which are often not
visible to the eye.
tooo4~) After the stone has been chipped by the pitching
blade assemblies, these assemblies are retracted and the
stone is then transferred to a discharge conveyor 44 by a
stone discharge and lift-off assembly 45 as will later be
described.
CA 02392934 2002-07-10
- 13 -
(000481 Referring now to Figures 8A and 8B, there is shown
the construction of the atop bar assembly 16 which positions
the stop bar 15 at a precise position to receive a concrete
block and align it with the pitching station 17. The stop
bar assembly 16 comprises a motor 46 which operates a
treaded shaft 47 whereby to slowly displace the stop bar
support frame at the proper location, as determined by the
controller 100, over the infeed conveyor 10. As hereinshown
the atop bar 15 is of sufficient length whereby the stone 11
has a surface thereof flush with the outer surface 15' of
the stop bar 15 to ensure good contact and proper
positioning. The infeed drive conveyors maintain the stone
flush thereagainst at the loading station 49. Whenever
different size stones are required to be pitched, the
control unit 100 will automatically actuate the motor 46 to
position the stop bar 15 at the proper position to center
the stone with respect to the pitching blades at the
pitching station. Accordingly, the entire machine is
automated to handle different size stones.
Iooo49~ With reference now to Figures 9A and 9B, there is
shown the construction of the pusher bar assembly 33 which
is secured under the infeed conveyor with the pusher bar
projecting between conveyor rolls 30'. For this purpose,
the pusher bar 50 is secured to vertical flanges 51 which
project between the rollers 10'. The vertical flanges axe
secured to a bar 52 which is secured to opposed carriages 53
having guide wheels 54 secured to each side of opposed guide
rods 55. The carriages are connected to endless chains 56
which are wound about drive sprockets 57 which are secured
to a drive rod 58 which is rotated by a motor 59. The
operation of the motor 59 is synchronized with other
operating assemblies and components of the machine and
controlled by the controller 100 whereby to engage a rear
surface of a block which is held by the stop bar and push it
slowly into precise position over the pitching platform 34
with the forward face of the stone projecting beyond the
CA 02392934 2002-07-10
- 14 -
plane of the pitching blades a predetermined distance over
the projecting edge 41 of the platform 34.
tooo5o~ With reference now to Figures 10A to 10C, there is
shown the construction of the stone discharge and lift-off
assembly 45. The assembly 45 consists of transfer fingers
60 which are held in parallel side-by-side spaced
relationship as shown in Figure 1 and are disposed in
alignment with the slots 40 provided in the pitching
platform and centrally located with respect to the pitching
station 17. The transfer fingers 60 are secured to a
support bar 61 which is attached at opposed ends thereof to
a carriage frame 62 provided with guide wheels or casters 63
also engaging opposed sides of a guide rod 64, as better
illustrated in Figure IOC. The carriage frame 62 is thus
displaceable along the guide rod 64 and it too is secured to
an endless chain 65 which is trained about a drive sprocket
66 and an idle sprocket 67.
Iooo5i~ Each of the carriages has a like endless chain
drive trained about drive sprockets 66 and 66',
respectively, which are secured to the drive rod 67 secured
to a drive motor 68. As hereinshown, the frames 69, which
support the carriage frame 62, are secured to a pivot rod 70
by bushings 71 whereby the frame assembly 69 can tilt up and
down in the direction of arrow 72. A follower head 73 is
secured to each of the frame assemblies and mounted on an
eccentric cam 74' which is rotated by a cam motor 74 to
cause the frame assembly to move up and down in the
direction of arrow 72. The cam motor and drive motor are
also driven in synchronism by the controller 100.
fooo5z) When a stone is being pitched at the pitching
station 17, the carrier frame 72 and the transfer fingers 60
are retracted away from the pitching station whereby the
lower horizontal pitching blade assembly can move upwardly
against the lower face of the projecting block. After the
pistons have retracted, the carriage frame 62 is moved
forwardly under the pitching platform 34. The cam 74 has
CA 02392934 2002-07-10
- 15 -
been rotated to maintain the frame assembly in its lowermost
position. Immediately upon the fingers reaching their
forward stroke under the pitching platform 34, the eccentric
cam is again rotated to lift the fingers 30 to project
through the slots 40 of the pitching platform 34 to
engagingly lift off the faced stone above the pitching
platform 34 and retract it over the discharge conveyor. The
transfer fingers 60 are also aligned between rollers 44' of
the discharge conveyor and the eccentric cam is again
rotated to lower the carrier frame 62 and transfer fingers
60 to deposit the pitched stone on the chain driven rollers
of the discharge conveyor 44 and automatically convey the
stone away in the direction of arrow 75 for further
processing, surfacing and/or stacking.
tooo531 As shown in Figure 14, when the stone 11 leaves
the discharge conveyor, the deep roughened surface 4 lies
vertical (sideways) on the discharge conveyor 44. If it is
desirable to further work this surface 4 to smooth sharp
edges and to further roughen the surrounding edges of the
stone, it is necessary to re-orient the stone with the deep
roughened surface 4 facing upwardly. This is achieved by an
inverting cradle 76, as shown in Figure 14 wherein a stone
is inverted to be fed by a further conveyor 85. The cradle
76 can also invert a stone lying flat and stand it on its
edge to be positioned on a squaring table 86 where a layer
of stones is accumulated and positioned side-by-side by
clamps 87 displaceable over the tale 86 on a transfer
conveyor rail 88.
(000541 The cradle 76 consists of a series of right angle
spaced-apart plates 77 which are disposed under a further
driven roller conveyor 78 in front of a stop plate 79. The
right angle plates 77, under the roller 78, are then
actuated or titled whereby to rise above the roller 78 and
engage the stone on its lowermost surface and tilt it on the
second series of right angle fingers 77" so that the stone
CA 02392934 2002-07-10
- 16 -
is inverted 90° and now lies with its roughened face facing
upwardly.
(00055 Referring to Figures 15A and 158, there is shown a
face smoothing and abrading station where a first series of
rotating impacting chains 81 impact the roughened chipped
face 4 of the stone I1 whereby to remove sharp stone points
90 and to further abrade the face and surrounding edges 82
of the stone 1l to give it a worn look. The conveyor 83
then continues to convey the stone under further smaller
rotating chain assemblies 81' to provide a less abrading
treatment of the surface and edges. At the end of this
smoothing and abrading station the stone can be turned again
to its original position for stacking and conveyed to a
squaring table where the stones are accumulated in a layer
and palletized. The stone smoothing and abrading equipment
will not be described in detail as it forms part of another
patent application.
tooo5sl Summarizing the operation of the concrete stone
facing machine of the present invention, a concrete stone is
conveyed at a predetermined oriented position to a loading
station adjacent a pitching station of the machine. The
stone is arrested at a predetermined position by a stop bar
at the loading station and precisely aligned with the
pitching station. The pitching station has two parallel
pairs of opposed blade assemblies, one pair being a
horizontal pitching blade assembly and the other pair being
a vertical pitching blade assembly. Each of the pitching
blade assemblies have a plurality of pitching blades secured
in side-by-side relationship. Each of the pitching blades
has a forward projecting cutting edge and a securing body
portion. A first group of pitching blades have their
cutting edges offset vertically and horizontally from the
cutting edges of a second group of pitching blades and
aligned along a straight cutting axis which is parallel to a
first straight cutting axis of the cutting edges of the
CA 02392934 2002-07-10
- i~ -
first group of pitching blades. The pitching blade
assemblies lie in a common vertical plane.
tooo5~) The pusher bar positions the stone at the pitching
station with the face to be pitched projecting a
predetermined distance beyond the common plane and over a
projecting edge of the pitching platform. A top clamping
bar then clamps the stone against the platform. The
pitching blade assemblies are sequentially displaced in
pairs or simultaneously to cause the pitching blades to
contact the surrounding surfaces of the walls about the face
which projects a predetermined distance from the platform
whereby to contact its associated surface of the stone.
During a second stroke of the hydraulic cylinders, the stone
surface is pitched to form the irregular rough surface with
deep penetrations in its surrounding surface contour to give
the face a deep rough texture and projection. The concrete
block having been pitched all around is then discharged by a
lift-off and discharge mechanism. The entire operation of
the machine is automatically controlled by a controller
which is preprogrammed to treat various sizes of stones.
tooo5s) The present invention is intended to cover obvious
modifications, provided such fall within the definition of
the accompanying claims which define the exclusive property
of the present invention.
